Step stool



Dec. 21, 1965 M. KING ETAL 3,224,530

STEP STOOL Filed April 10, 1963 4 Sheets-Sheet l INVENTORS. MARV/N KING W/LL/AM M SCHMIDT STANLEY E. THORWALDSE/V M g/w/V A TTOR/VE Y Dec. 21, 1965 M. KING ETAL STEP STOOL 4 Sheets-Sheet 2 Filed April 10 1965 Fig. 9.

INVENTORS. MARI/l/V Kl/VG WILL/AM M SCHM/DT By S7I4/VLEY E. THORWALDSE/V 4 an hau 4 A TTOfF/VE Y Dec. 21, 1965 M. KING ETAL STEP STOOL 4 Sheets-Sheet 4 Filed April 10, 1963 INVENTORi MARV/N K/NG W/LL/AM SCHMIDT B SM/VLEY El THORWALDSE/V M/Z W A TTOR/VE) United States Patent Office 3 ,224,530 Patented Dec. 21, 1965 3,224,530 STEP STOOL Marvin King, Oak Park, William M. Schmidt, Grosse Pointe Farm, and Stanley E. Thorwaldsen, Livonia, Mich, assignors, by mesne assignments, to Samsonite Corporation, Denver, Colo., a corporation of Colorado Filed Apr. 10, 1963, Ser. No. 271,909 4 Claims. (Cl. 182-33) This invention relates to step stools, and more particularly to foldable step stools.

Among the objects of this invention are to provide a novel step stool; to provide such a step stool which may be folded when not in use; to provide such a step stool which is readily folded and unfolded; to provide such a step stool having at least one step and a seat; to provide such a step stool which cannot tip over when one is standing on a step; to provide such a step stool which is comfortable to sit on; to provide such a step stool which is. easy to use; and to provide such a step stool which is of relatively simple construction, light in weight and economical to manufacture.

Additional objects and the novel features of this invention will become apparent from the description which follows, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front perspective view of a step stool of this invention;

FIG. 2 is a vertical section, taken through the center of the stool shown in FIG. 1;

FIG. 3 is a rear elevation of the step stool of FIG. 1;

FIG. 4 is a side elevation of the step stool of FIG. 1, but in partly folded or closed position;

FIG. 5 is a side elevation of the step stool in folded position;

FIG. 6 is a rear elevation of the step stool in folded position;

FIG. 7 is a front elevation, on an enlarged scale, of the step stool in folded position;

FIG. 8 is a vertical section, taken along line 8-8 of FIG. 7, showing further details of the construction of the step stool;

FIG. 9 is a bottom plan View, on an enlarged scale, of the seat of the step stool;

FIG. 10 is a vertical section, on a further enlarged scale, taken along line 10-10 of FIG. 9 and condensed at one end;

FIG. 11 is a fragmentary, vertical section, on a further enlarged scale, taken along line 11-11 of FIG. 9 but showing the seat prior to the attachment of a pair of brackets;

FIG. 12 is a fragmentary, vertical section, similar to FIG. 11, but taken along line 12-12 of FIG. 9; and

FIG. 13 is a fragmentary, vertical section, similar to FIG. 11, but take along line 13-13 of FIG. 9.

In accordance with this invention, a foldable step stool, as in FIGS. 13, includes a seat S supported by a rearwardly extending, front leg frame F and a forwardly eX- tending, rear leg frame R, and a step P supported by a step frame T. During use, the lower end of front leg frame F rests on the floor at a position forwardly of the front edge of step P, as in FIG. 2, so that the weight of a person on step P, either standing thereon or stepping up onto seat S, will not overbalance the stool. Also, the seat S is contoured, as described later, to provide maximum comfort to the user, who may sit on the stool with his or her feet on step P, or may incline the legs forwardly to clear step P. When it is desired to fold the stool, as for storage, an upward force under the front edge of step P, as by one hand, will cause the step frame T and step P to pivot about the front leg frame F, as to the intermediate position of FIG. 4, and then to the folded position of FIG. 5. During such movement, the other hand may be placed on either the front or rear edge of seat S, the latter being preferable, since the seat S may thereby be assisted in pivoting about the upper end of rear leg frame R to the position of FIG. 4 and then to the position of FIG. 5. During such pivotal movement of step P and seat S, the lower ends of front leg frame F and rear leg frame R are moved together by a pair of links L, which pivotally interconnect step frame T and rear leg frame R. Simultaneously, the upper end of rear leg frame R slides forwardly in a pair of brackets B, mounted on the underside of seat S, from the position of FIG. 2 to the intermediate position of FIG. 4 and then to the folded position of FIG, 5.

As will be evident from FIGS. 6 and 7, in the folded position, the step P and step frame T fit within the front leg frame P, which in turn fits within the rear leg frame R, while the seat S overlaps the upper portions of the leg frames and step P. As will be evident from FIG. 5, the stool in folded position is quite narrow, from front to rear, and thus may occupy a relatively narrow space, as in a closet. For example, in the case of a stool in which the step P is about 10% inches from the floor and the center of seat S about 22 /2 inches from the floor in unfolded or use position, the folded stool is about 27 /2 inches in maximum height, about 18 inches in maximum width and about 5 inches thick at the point of maximum thickness, i.e., at the rear or lower edge of seat S. The stool may also be tipped against a wall, in which event, if the folded stool is visible, it may be preferred to place the front facing the wall, so that the rear is visible, as in FIG. 6, to provide a more pleasing appearance. For unfolding, the seat S may be lifted and the step P pushed downwardly also, as a reverse of the folding operation. Thus, the stool is readily folded or unfolded and also readily stored.

The front leg frame F, as in FIGS. 1-3, is generally U-shaped, having a pair of spaced front legs 10 and 11 connected at their upper ends by an integral cross bar 12. Similarly, the rear leg frame R is generally U- shaped, having a pair of spaced rear legs 13 and 14 connected at their upper ends by an integral cross bar 15 which is wider than cross bar 12 so that front legs 10 and 11 will nest within rear legs 13 and 14 when the stool is folded, as described above. Conveniently, front leg frame F is pivoted to rear leg frame R, intermediate the step and seat, by means of rivet head, pivot pins 16, while the leg frames are separated slightly, to insure easier pivotal movement, by bushings 17, as in FIG. 7, through which the respective pivot pins extend. When the stool is in open position, as in FIG. 1, the front leg frame and rear leg frame will be crossed. Conveniently, the lower end of each of the stool legs is provided with a rubber or plastic foot 18 to prevent the stool from sliding on a floor or other surface, while the leg frames are conveniently formed from metal tubing.

Step P may be stamped from sheet metal to provide spaced, laterally extending ribs 20 and a downturned peripheral edge 21, the lower end of which is curled back onto itself on the inside, to obviate sharp edges or corners. Also, a raised portion 22 at each side of the step may be provided to prevent the foot of a user from accidentally sliding off the step at either side. The step frame T is generally U-shaped and includes a pair of elongated, parallel legs or bars 23 and 24 which are spaced apart, such as a distance such that the centerlines thereof substantially coincide with the outer edges of step P, as in FIG. 7. From legs 23 and 24, inwardly convergent portions 25 and 26, respectively, extend beneath step P to an integral cross bar 27, which is attached to the underside of step P adjacent the front end thereof, as by a pair of spaced rivets 28, as in FIGS. 1, 7 and 8. The upper head of each rivet 28 is conveniently received in a well formed in the upper surface of step P, so that the heads of the rivets will not protrude. In the open or use position, the step frame T angles upwardly at a small angle, from the rear to the front, as in FIG. 2, with the rear ends of legs 23 and 24 engaging the underside of a conveniently tubular cross rod 29, as in FIG. 3, the ends of cross rod 29 being attached to rear legs 13 and 14, as by being flattened and welded to the rear of the rear legs. The step frame T is also pivotally connected to front legs and 11, as by rivet head, pivot pins 30, with bushings 31, as in FIG. 7, through which the respective pins 30 extend, separating the front legs and step frame to insure easier pivotal movement. The rear of step P is reinforced by an angle 32, extending across the underside of the step and attached thereto, as by a pair of spaced rivets 33. The upper heads of rivets 33 are preferably countersunk in the upper surface of step P, while, at each rivet 33, angle 32 is provided with a boss 34 to accommodate the well in the step. In order to support the rear of step P at a position level with the front, angle 32 is provided with depending flanges 35 and 36 at the opposite ends thereof, which flanges extend downwardly on the inside of legs 26 and 27, respectively, of the step frame T, and are conveniently secured thereto by pivot pins 30. In addition, inner flange 37 of angle 32 extends laterally beyond each end flange 35 and 36 and abuts angular portions 25 and 26 of step frame T, as in FIGS. 2 and 8.

Each link L, as in FIGS. 7 and 8, is pivotally connected at one end to leg 23 or 24 of step frame T, as by a pivot pin 38, while the opposite end 39 is offset and provided with a collar 40 which is pivotal about rod 29. Of course, during assembly, the collars 40 must be slipped onto rod 29 before the latter is welded in place. The rear end of each leg 23 and 24 of step frame T is conveniently closed by a plug 41, as in FIGS. 4 and 6.

Each bracket B may be stamped from sheet metal, and is attached to the underside of seat S, as by rivets 42 and 43 of FIGS. 9 and 10, and cooperates with a rod 44, the front end of which holds cross bar of leg frame R in position and the remainder of which permits cross bar 12 of leg frame F to move between the positions of FIGS. 2 and 5. Rivets 42 and 43 are conveniently attached to seat S in a manner described later. As in FIG. 9, each bracket B has a peripheral flange 45 which extends around the bracket and engages the underside of seat S, conforming to the contour thereof, as in FIG. 8, except for a raised portion 46 at the rear, as in FIG. 10, at the position of rivet 43. Each bracket is shaped to provide a flat, central land 47 which is engaged by cross bar 12 and is spaced from but slants away from the underside of seat S, from front to rear, as in FIG. 10. An inclined side wall 48 connects land 47 with flange 45 at each side, with a similar wall 49 at the rear. At the front, land 47 separates into two arcuate lands 50, at each side of a well 51, as in FIG. 9, at the flat bottom 52 of which, as in FIG. 10, rivet 42 is attached. Forwardly of well 51, the bracket is upset to provide a knob 53, which in cooperation with rod 44 retains cross bar 15 in a socket 54, from which a flat 55 extends obliquely to an inclined front wall 56 of the bracket. Flat 55 is provided with a hole which receives the angular front end 58 of rod 44, having an upset head 59 to connect the rod 44 with the bracket. As will be evident, the angular front end 58 and an adjacent portion of rod 44 hold cross bar 15 in socket 54. Rod 44 parallels flat land 47 and arcuate lands 50, as in FIG. 10, while adjacent its rear end, the rod 44 is bent to provide a nearly perpendicular portion 60 which abuts rear wall 49 and a flattened rear end 61 which engages raised section 46 and is provided with a hole for attachment by rear rivet 43.

Each rivet 42 and 43, as in FIGS. 11 and 13, is provided with a. head '63 which is conveniently flash welded to the underside of seat S, as by one electrode inserted in a hole 64 in the rivet, which is hollow, and a ring electrode placed around head 63. By use of both a relatively high voltage and amperage, for a controlled, very short time, the head 63 of the rivet may be welded to the underside of seat S without unduly heating the opposite side, for :a purpose described later. Due to the head 63 of each rivet 42 and 43, the raised portion 46 of a peripheral flange 45 is necessary to enable the peripheral flange to be held tightly against the underside of seat S, while the bottom flat 52 of well 51 is also spaced from the underside of seat S to accommodate head 63 of rivet 42. For assembly purposes, the rear end 61 of rod 44 is inserted through the hole in flat 55 of the bracket, until head 59 reaches the flat 55. Then, rod 44 may be shifted to one side and bracket B placed against the underside of seat S, with rivets 42 and 43 extending through appropriate holes in flat 52 and portion 46, respectively. Then, the hollow end of rivet 42 may be riveted over onto a washer 65 to hold the bracket in position. After both brackets B are similarly partly installed, leg frames F and R may be placed in position, then rod 44 of each bracket moved into position over cross bars 12 and 15 and the rear end of each rod 44 placed over the corresponding rear rivet 43 and the hollow end of the latter riveted over onto the flattened end 61. As will be evident, such as assembly operation may be carried out quickly and expeditiously.

To provide an attractive appearance and also to provide greater comfort during use, the upper surface of seat S, which is conveniently stamped or pressed from metal, is provided with a covering 67 which is conveniently a suitable plastic, such as vinyl, and may be provided in a desired color or colors, as in a leather simulating or other pattern. The seat S is conveniently cut to shape and the covering 67 bonded thereto under pressure while fiat, as by a resin adhesive, to provide better adherence. Then, the seat may be formed to shape, as in a suitable press, as to provide the contour shown in FIGS. l-5, 8 and 10, including a downwardly curved front end 68 and an upwardly curved rear end 69, together with upwardly curved sides 70, which increase in height from front to rear. The generally rectangular, central portion of the seat, between the front and rear ends and the sides, is preferably slightly concave, both from front to rear and from side to side, so that the contour of the seat is thus such that the seat is comfortable to sit in. As will be evident from FIG. 2, the central portion of the seat will be level during use, although slightly concave, since rod 44 slants rearwardly downwardly in the unfolded position of the stool. Thus, the seat provides a level surface for standing. In addition, the peripheral edge 71 of the seat is curled around onto itself, as in FIGS. 10-13, not only to obviate sharp edges or corners, but also to place the peripheral edge of the covering 67 in a protected position and thereby prevent the possibility of accidental blows or impacts by a sharp instrument from separating the covering from the metal of the seat.

As noted above, the covering 67 is more conveniently applied while the metal strip, from which seat S is formed, is flat. Also, the seat is more conveniently formed to shape before rivets 42 and 43 are attached to the underside thereof. Although the metal of the seat is not adversely afliected by the heat of welding rivets 42 and 43 thereto, the plastic covering 67 might be affected. Thus, the flash welding of the rivets 42 and 43, as described above and Which can be carried out so that the plastic covering 67 is not unduly heated, permits the covering to be bonded to the seat in a more convenient manner. As will be evident, if rivets 42 and 43 extended through the seat, the heads thereof would extend or wells in the seat would be necessary to countersink the heads. In either event, irregularities in the surface of the seat would be produced, which would tend to cause discomfort on the part of the user.

From the foregoing, it will be evident that the objects hereinbefore set forth have been fulfilled to a marked degree. The invention provides a foldable step stool, which will not tip over when one is standing on the step. This is true because the step is located inwardly of the ends of the front legs, so that any weight on the step is always supported between the front and rear legs. In addition, a stool has been provided which may be easily folded, by lifting upwardly on the step, and may be easily unfolded, by lifting upwardly on the seat. Thus, the step frame is pivoted between the front legs and a pair of links pivoted to the rear legs to cause the rear legs to pivot with respect to the front legs upon lifting the step, so that the stool may be easily and quickly folded. Also, the upper end of the front leg frame is slidable between the rods and brackets mounted on the underside of the seat, causing the front leg frame to pivot when the seat is lifted, so that the stool is easily and quickly unfolded. In storage position, the stool is compact, since the step and step frame fit within the front leg frame, which in turn fits within the rear leg frame, while the seat overlies portions of the leg frames and step. Furthermore, the stool is easy to use, is of relatively simple construction, has an attractive appearance, and is durable in construction.

Although the stool of this invention has been shown and described as having one step, it will be evident that a higher stool with additional steps may be provided, the upper steps being pivotally interconnected with the lower step and nesting within the front leg frame with the stool in storage position.

Although a preferred embodiment of this invention has been illustrated and described, it will be understood that various changes and variations may be made, without departing from the spirit and scope of this invention.

What is claimed is:

1. A step stool comprising a pair of front legs; a pair of rear legs pivoted to said front legs above the center of height thereof so that, with said legs in open position, the upper portion of said rear legs will be disposed above said front legs and the upper portion of said front legs will be disposed above said rear legs; a seat pivotally attached at its front to the upper portion of said rear legs and movably connected to the upper portion of said front legs; a step frame having a pair of spaced, rearwardly extending bars, said step frame being pivotally connected to said front legs below the pivotal connection of said front and rear legs; a step mounted on the front of said step frame; a cross rod extending between said rear legs intermediate the ends thereof; links pivotally connecting a bar of said step frame to said rear cross rod, said bars of said step frame being adapted to engage the underside of said rear cross rod to maintain said step in normal position; and an angle attached to the underside of said step and having an ear depending from each end thereof, each said ear being connected to a pivotal connection between a front leg and said step frame.

2. A step stool comprising a pair of front legs interconnected by a top cross bar; a pair of rear legs interconnected by a top cross bar and pivoted to said front legs above the center of height thereof so that, With said legs in open position, the upper portion of said rear legs will be disposed above said front legs and the upper portion of said front legs will be disposed above said rear legs; a seat connected to said front and rear legs; a step frame having a pair of spaced, rearwardly extending bars, said step frame being pivotally connected to said front legs below the pivotal connection of said front and rear legs; a step mounted on the front of said step frame; a cross rod extending between said rear legs intermediate the ends thereof; links pivotally connecting a bar of said step frame to said rear cross rod, said bars of said step frame being adapted to engage the underside of said rear cross rod to maintain said step in normal position; a pair of spaced brackets, each having a peripheral flange engaging the underside of said seat, side walls extending from said flange to a land which is disposed angularly to said seat, a knob at the front end of said land and a socket forwardly of said knob; and a pair of rods, each attached at its front end to a bracket forwardly of said socket and at its rear end to said bracket rearwardly of said land, each rod being disposed in parallel relation to said land of said bracket, said cross bar of said rear legs being held for pivotal movement in said sockets of said brackets by said rods and said cross bar of said front legs being restrained for sliding movement along said lands by said rods.

3. A step stool, as set forth in claim 2, wherein each said bracket is attached to the underside of said seat by a front rivet and a rear rivet, said land being divided adjacent said knob into a front land disposed on each side of a well for receiving said front rivet; and said rear rivet attaching both the rear end of said bracket and the rear end of said rod to the underside of said seat.

4. A step stool, as set forth in claim 3, wherein the upper surface of said seat is provided with a plastic covering; and each said rivet is a hollow rivet having an enlarged head flash welded to the underside of said seat.

References Cited by the Examiner UNITED STATES PATENTS 714,562 11/1902 Crandall et al. 297-57 2,298,450 10/1942 Baker 297-183 2,828,804 4/1958 Schwinn 248-432 3,011,585 12/1961 Hamilton 182-33 3,025,101 3/1962 McKinnie 182-125 3,031,243 4/1962 Crevoi 108-120 3,033,511 5/1962 McAfee 248-432 3,042,140 7/1962 Basile et al. 182-125 3,058,544 10/1962 Rossi et al. 182-129 3,059,722 10/1962 Rouse 182-156 FOREIGN PATENTS 669,494 8/ 1929 France. 466,295 5/ 1937 Great Britain.

HARRISON R. MOSELEY, Primary Examiner. FRANK B. SHERRY, Examiner. 

1. A STEP STOOL COMPRISING A PAIR OF FRONT LEGS; A PAIR OF REAR LEGS PIVOTED TO SAID FRONT LEGS ABOVE THE CENTER OF HEIGHT THEREOF SO THAT, WITH SAID LEGS IN OPEN POSITION, THE UPPER PORTION OF SAID REAR LEGS WILL BE DISPOSED ABOVE SAID FRONT LEGS AND THE UPPER PORTION OF SAID FRONT LEGS WILL BE DISPOSED ABOVE SAID REAR LEGS; A SEAT PIVOTALLY ATTACHED AT ITS FRONT TO THE UPPER PORTION OF SAID REAR LEGS AND MOVABLY CONNECTED TO THE UPPER PORTION OF SAID FRONT LEGS; A STEP FRAME HAVING A PAIR OF SPACED, REARWARDLY EXTENDING BARS, SAID STEP FRAME BEING PIVOTALLY CONNECTED TO SAID FRONT LEGS BELOW THE PIVOTAL CONNECTION OF SAID FRONT AND REAR LEGS; A STEP MOUNTED ON THE FRONT OF SAID STEP FRAME; A CROSS ROD EXTENDING BETWEEN SAID REAR LEGS INTERMEDIATE THE ENDS THEREOF; LINKS PIVOTALLY CONNECTING A BAR OF SAID STEP FRAME TO SAID REAR CROSS ROD, SAID BARS OF SAID STEP FRAME BEING ADAPTED TO ENGAGE THE UNDERSIDE OF SAID REAR CROSS ROD TO MAINTAIN SAID STEP IN NORMAL POSITION; AND AN ANGLE ATTACHED TO THE UNDERSIDE OF SAID STEP AND HAVING AN EAR DEPENDING FROM EACH END THEREOF, EACH SAID EAR BEING CONNECTED TO A PIVOTAL CONNECTION BETWEEN A FRONT LEG AND SAID STEP FRAME. 